Super capacitors (high capacitance devices in a smaller form factor) are a relatively new technology. Their large capacitance value makes it possible to use them as energy sources in applications that typically would have involved the use of chemical batteries. For example, super capacitors may be used to power memories and logic that moves the contents of a volatile RAM into a nonvolatile memory during a power failure or system shutdown.
Current designs employing super capacitors use a fixed approach, that is, a capacitor value is selected that is adequate over the product's life, regardless of degradation of the capacitance value. Super capacitors have an observed behavior of substantial reduction in value after repeated charging and discharging cycles. Because of this, either a larger value than initially required is selected, or the possibility of a failure later in a product's life is possible. Super capacitors also degrade due to other factors such as elevated temperature. Because of this a higher capacitance value is initially required in a product's life in order to compensate for the expected reduction in capacitance as the product ages.
Having a larger capacitance initially than what is actually required has a negative effect—it takes longer to charge to the usable voltage and thus delays the ability to permit operation of the device that is powered or potentially powered by the capacitor.